In a report to the Security Council circulated Friday, Ban said he was particularly concerned about the firing of rockets from Lebanon into Israel, the discovery of an arms and ammunition depot in southern Lebanon, and explosions and a fire in that area which are still under investigation.

The secretary-general reiterated his call for full implementation of Security Council resolution 1701 that ended the 34-day Israeli-Hezbollah war including the disarmament of all armed groups in Lebanon, adherence to the arms embargo on Lebanon by all countries, especially those with ties to Hezbollah, demarcation of the Lebanese-Syrian border, and an end to Israeli overflights.

Ban also called on Israel and Syria to respond to the provisional definition of the disputed Chebaa Farms area on Lebanon's border with Syria's Israeli-occupied Golan Heights, and urged Israel to withdraw from the disputed village of Ghajar and an adjacent area that are on the Lebanese side of a U.N.-drawn boundary "without delay."

While the situation in the southern Lebanon area where the U.N.'s more than 13,000-strong peacekeeping force operates "remained generally quiet," the secretary-general expressed "serious concern" at a series of recent incidents and condemned all violations of the cease-fire resolution.

He singled out the firing of rockets into Israel on Sept. 11 and Oct. 27 _ the fourth and fifth such attacks from Lebanon in 2009 _ which Israel responded to with artillery fire, and the discovery of an arms and ammunition depot in a building under the control of Hezbollah on July 14.

The secretary-general also expressed concern at an incident on Oct. 12 involving a fire, possibly caused by an explosion, in the garage of a residential building in Tayr Falsay owned by a Hezbollah official. He said some items were moved to a nearby village before U.N. peacekeepers and the Lebanese army arrived.

Later, "UNIFIL and the Lebanese Armed Forces inspected both locations but found no signs of an explosion or of unauthorized arms and ammunitions at either of the two locations," Ban said. "It appears, however, that evidence may have been tampered with at both locations."

UNIFIL is also still investigating two explosions in the area between Houla and Meiss el-Jebel on Oct. 17 and Oct. 18, he said.

"Preliminary indications are that the explosions were caused by explosive charges contained in an unattended, underground Israel Defense Forces sensor system," he said.

The secretary-general said UNIFIL and the Lebanese army discovered a battery pack buried in the ground at the same location, which was apparently a third part of the sensor system, and are now trying to establish how and when the device was installed and how it was detonated.

Ban noted that the presence of Israeli devices with explosive charges on Lebanese territory is a violation of resolution 1701.